Stapling device



May 15, 1962 A. L. ROBBINS STAPLING DEVICE 2 Sheets-Sheet l Filed Oct. l0, A1957 May 15, 1962 A. L.. ROBBINS 3,034,128

STAPLING DEVICE Filed Oct. lO, 1957 2 Sheets-Sheet 2 United States This invention relates generally to the field of staple tackers, of the type in which a staple is driven directly into material having considerable depth in such manner that the ends of the staple are not bent but rather secure an attachment in a manner analogous to that of a double pointed brad. Such devices are known in the art, and the invention relates to improvements in constructional details.

In devices of this type, the staple is driven home by action of a spring pressed driving block to which there is attached a blade of width substantially equal to that of the staple. The block is moved in a direction to compress the spring by pressing upon a pivotally mounted lever which transmits motion through -a pawl as the engaging edge thereof executes orbital motion. The edge is engaged within a depression which is cleared as the pawl moves, and at a point where the block is moved to substantially fully compress the spring. The block possesses considerable inertia, and with repeated usage, the impact of the block upon structure adapted to arrest the motion of the same eventually fractures and breaks the frame upon which the block arresting structure is mounted. Various attempts have been made to reinforce the structures subject to breakage, with varying degrees of success, but no structure in the prior art has succeeded in distributing the impact load over a relatively wide area.-

Another difiiculty which has been experienced in using staple tacking devices of the class described has been the relatively frequent tendency to jam in such manner that two adjacent staples are forced into the channel of a width suflicient to accommodate a single staple necessitating substantial disassembly of the device to clear the blockage. The present invention contemplates not only the provision of readily removable means to accomplish the clearing of a jam once the same has occurred, but also the incorporation of means for eliminating the principle cause of jamming.

Another object of the invention lies in the provision of improved means for feeding strips of temporarily integrated staples to the point of discharge.

A further object of the invention lies in the provision of improved staple feeding latching means which facilitates the loading of additional staples within the device as the same are required.

Still another object of the invention lies in the provision of an interchangeable driving blade which can be assembled within the device in operative relationship only in the proper position.

A further object of the invention lies in the provision of structure of the class described in which the cost of fabrication may be of a reasonably low order, comparable with devices existing in the prior art.

These objects, as well as other incidental ends land advantages, will become more clearly apparent during the course of the following disclosure, and be pointed out in the appended claim.

On the drawing, to which reference will be made in the specification, similar reference characters have been employed to designate corresponding parts throughout the several views.

FIGURE 1 is a vertical central longitudinal sectional view showing an embodiment of the invention.

FIGURE 2 is a vertical transverse sectional view 4as seen from the plane 2 2 on FIGURE l.

atent Grta Y matias Patented May 15, 1962 ice FIGURE 3 is a vertical transverse sectional View as seen from the plane 3-3 on FIGURE 1.

FIGURE 4 is a view in perspective showing a removable front door which comprises a part of the embodiment.

FIGURE 5 is a fragmentary enlarged exploded view in perspective showing the structure of the staple guiding spring and its mounting upon a bumper plate, which structure comprises parts of the embodiment.

FIGURE 6 is an exploded view in perspective of the staple feeding latching means.

FIGURE 7 is an enlarged fragmentary view in perspective showing the relation of the bumper plate structure to the main frame element.

FIGURE 8 is an exploded view in perspective showing the relation between the driving block and driving blade members which comprise .part of the staple driving means.

FIGURE 9 is a view in perspective of the bumper plate showing the bending of a portion thereof for purpose of prestressing.

In accordance with the invention, the device, generally indicated by reference character 10, comprises broadly: a main frame element 11, staple feeding means 12, and staple driving means 13.

The main frame element 11 includes a pair of main frame members 17 and 1'8 (see FIGURES 1, 2 and 3) and a front door member 19 (see FIGURE 4), the members 17-19, inclusive, enclosing a bumper plate member 20.

The main frame members 17 and 18 aresubstantially similar, each including a planar side wall 24, a top wall 26 and an end wall 27 which define a iirst opening 28 and a second opening 29. A centrally disposed opening 30 is formed by a continuous inner wall 31 on each of the members 17 and 18, and a horizontally disposed tab engaging opening 32 is provided -adjacent a forward edge 34 as best seen on FIGURE 7 on the drawing.

The opening 32 is provided with a rounded forward edge 33 to prevent the localization of stresses which might otherwise cause rupture with continued use.

The front door member 19 is of somewhat heavier planar stock than the main frame members 17 and 18, and includes a vertical end wall 35 and a pair of side walls 36 and 37. A vertically disposed longitudinal channel 38 extends outwardly from the inner surface of the end wall 35, and the side walls 36 and 37 are provided with aligned openings 39-41 and 40-42. Removable pins 43 and 44 (see FIGURE l) extend through the front door member, and maintain the same in detachable engagement with the main frame members. v

'I'he bumper plate member 20 (see FIGURES 1, 5 and 9) includes a pair of vertical walls 46 and 47 the extent of which is indicated in FIGURE l which engage the inner surfaces of the frame member 17 and 18, respectively, and are interconnected by a bridge portion 48 from which extends a bumper portion 49. The interconnecting portion 50 is of slightly narrowed width to permit prestressing of the bumper portion 49 with respect to the bridge portion 48 as best seen on FIGURE 9. This is accomplished by slightly bending the members, and during assembly of the device the set is maintained by forcing the bumper portion 49 into engagement with the openings 32. The bumper portion 49 is provided with a pair of tabs 55 and 56 which engage the aforementioned openings 32, the same having a centrally disposed opening 57 whereby rivet means 58 may maintain a rubber bumper member 59 thereupon. During operation, the shock of the impact of the staple driving means is transmitted to the main frame element through the tabs 55 and 56, and also through the bridge portion 48 to the vertical walls Walls 82 and vS3 which are generally symmetrical.

Y s s f 46 and 47, through the pins` 53 (see FIGURE 1) and the openings S1 to the main frame element.

The staple Vfeeding means 12 includes a staple guiding spring 62, a staple guiding channel member 63, a staple guiding core 64, a pusher member 65, a pusher guide rod 66, a pusher spring member 67, and a latch member 68 together with latch spring member 69 and a pair of latch engaging members 7 t) bent up from the frame members 17 andr18.

The channel member 63 includes a bottom Wall 71 (see FIGURE 2), side Walls 72 and 73, and top walls 74 and 75 which define a space 76 therebetween.

The staple guiding core 64 is disposed within the channel member 63 and includes a bottom wall 78, and side walls 79 and 80.

The latch member 68 includes aV rear Wall 81 and side Each of the side walls 82-83 includes a forward edge 84, the lower portion of which forms a cam surface 8S adapted to contact a corresponding camming surface 86 on the latch engaging members 70. Disposed immediately be hind the cam surface S on each of the side walls 82-83 is a locking notch 87 adapted to receive the entire latch v engaging member 70.

The latch spring member 69 includes a latch member" engaging portion 90 which is secured to the latch member by rivets 91 which engage corresponding openings 92. in

the latch member. The resilient portion 93 is provided with a camming portion 94 which is adapted to contact the inner surface of the continuous wall 31 at the point indicated by reference character 95.

Referring to FIGURE 5 on the drawings, the staple guiding spring 62 includes a mounting portion 97 secured to the undersurface of the bridge portion 48 and a resilient portion 98 having a forward edge 99. Referring to FIG- URE l, it will be observed that when the resilient portion 98' is pressed between the top walls 74 and 7S, the forward edge 99 extends to a point sucient to cover the penultimate stape in the group generally indicated by reference character 100. Y

The staple driving means 13 includes a driving block 107, a` driving block spring 108y anchored at the upper end .by Va guide 109, a driving blade 110, a pivotally mounted pawl 111, a pivotally mounted lever 112 which extends from the opening 2S, a lever return spring 113 and a lever retaining loop 114, all of which function in a :manner Well known in the art. Y

- The driving block 7'is best seen on` FIGURE S'of the drawing, and include a central bore 116v in which the spring 108 is disposed, a pair of side surfaces, onezof which is indicated by reference character 117, a front surface 118, alower surface 119 (see FIGURE 1) and a rearward surface 121i.V A notch 121 is provided for engaging the pawl 111. Disposed on the upper portion of the front surface 118 is a relatively wide projection 122, the width of which corresponds to that of the channel 38. Disposed vbeneath the projection 122 is a second elongated projection'123 which is laterally offset with respect to the principal axis of the driving block.

The driving blade is of elongated configuration, and is adapted to reciprocate vertically Within the lower portion Yof the channel 38. It includesY a top edge 1,25 adapted to rest against the lowermost edge of the projection 122, a -chamfered bottom edge 126, side edges 127 and 128 and an oiset rectangular opening 129 which corresponds to the location of the projection 12,3. From a consideration of FIGURE 8, it will be apparent that the blade can be assembled within the device only in the relation in which the chamfered. edge extends in a direction away fromY the front door member 19, since should the position be reversed, the blade will not t against the driving block;

During operation, the arrangement of the chamfered edge 126 will tend to prevent the blade from shearing more than one staple trom the strip of staples being fed and the spring 62 serves to keep the strip firmly positioned such that individual staples may be readily severed. In the event that certain of thev staples become loose when within the strip, the spring replaces the action of the glue normally employed to maintain the staples in strip form, thereby materially lessening the likelihood of the occurrence of a jam.

It may thus be seen that IV have invented novel vand highly useful improvements in stapling devices, in which there haveV been provided a number of useful structural improvements. The provision of a removable 'front door permits the rapid interchange of driving blades, as well as the convenient removal ot the same should it become necessary to clear any jam which might occur. By virtue of a prestressed bumper plate member, the occurrence of metal fatigue -is materially reduced, thus increasing the useful life of the device. By provision of a resilient spring member having a lineof action parallel to the line of discharge of the staple and positioned to cover all of the staples at the discharge end ofra strip of staples with Vthe exception of that in position for discharge, the tendency to jam is materially reduced. All of the above advantages are obtained without materially increasing the cost of manufacture of the device as compared with similar devices known in the art.

I wish it to be understood that I do not consider the invention limited tothe precise details of structure shown and se't forth in this specication, for obvious modifications will occur to those skilled in the art to which theA connected respectively to said iirst and second frame (it)V References Cited in the tile of this patent i UNITED STATES PATENTS 216,144 Brown lune 3, 1879 1,601,324 Reynolds Sept. 28, 1926 2,143,384 Peterson Ian. 10, 1939 2,437,039 Peterson Mar. 2, 1948 2,580,065 Anstett Dec. 25, 1951 

